Britain today pledged an immediate £5m to help the relief effort in Burma and warned the ruling military junta to allow aid agencies proper access to the country.
Douglas Alexander, the secretary of state for international development, said a team of specialists from the Department for International Development (DfID) would also be deployed.
"By any measure, we are talking about an extremely serious humanitarian situation here," he told the BBC's World at One programme.
"But there is another key issue, which is whether we are able to secure the level of access for the international humanitarian effort that is required.
"That's why … we are urging the government of Burma to allow the international community access both for assessment purposes in the first instance and then to provide the relief - the water, the food, the shelter - that's so desperately required by the people affected."
Burmese authorities, struggling to cope with the scale of the disaster, have admitted they need international assistance. However, UN officials are still waiting for visas allowing them access.
The US president, George Bush, joined the calls for experts to be allowed in to help the hundreds of thousands of people who have been made homeless. "The United States has made an initial aid contribution, but we want to do a lot more," he said.
"But in order to do so, the military junta must allow our disaster assessment teams into the country. So our message to the military rulers is: let the United States come and help you help the people."
The £5m DfID aid package was welcomed by campaigners for democracy and human rights in Burma. The Burma Campaign UK had previously criticised the government and the UN for being slow to act.
"This aid is very welcome - it is desperately needed," Mark Farmaner, the organisation's director, said. "There must now be increased pressure on the regime to allow aid to be delivered to those in need."
